2.07 Cytoskeleton Flashcards

0
Q

Provides rigid physical support for certain parts of cells

A

Cytoskeleton

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1
Q

Extensive intracellular network of filamentous structures extending throughout the cytoplasm

A

Cytoskeleton

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2
Q

Physical support for certain parts of cells

A

Intracellular scaffolding

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3
Q

Function of cytoskeleton

A

Structural support
Cell motility
Cell regulation

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4
Q

Stabilize and balance opposing forces
Spherical/partially spherical shell structure of lattice shell based on a network of great circles on the surface of a sphere

A

Geodesic dome

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5
Q

Changes in cell location and limited movements of parts of the cell

A

Motility

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6
Q

Transmit mechanical signals that rearrange the nucleoli and other structures

A

Cell regulation

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7
Q

3 main types of cytoskeletal fibers

A

Microtubules
Microfilaments
Intermediate filaments

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8
Q

Types of cytoskeleton can be distinguished

A

Biochemically

By TEM

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9
Q

Contain alpha and beta tubulins

Grow or shrink as more tubulin molecules are needed or removed

A

Microtubules

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10
Q

Important for directing intracellular traffic

Motor molecules also carry vesicles or organelles to various destinations along monorails provided by cytoskeleton

A

Polarity

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11
Q

Function of microtubules

A

Mitosis spindle
Intracellular trafficking of vesicles
Cilia and flagella
Axoplasmic flow of materials along neuronal processes

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12
Q

Locomotory cells

A

Kinesins

Dyneins

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13
Q

Central structural supports in cilia and flagella

A

Microtubules

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14
Q

Move unicellular and small multicellular organisms by propelling water past the organism
Move fluid over a surface if anchored on large structures

A

Microtubules

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15
Q

Move more like oars with alternating power and recovery strokes

A

Cilia

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16
Q

Cilia generate force ______ to the axis of the cilia

A

Perpendicular

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17
Q

Undulatory movement

A

Flagella

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18
Q

Flagella

Eukaryotic

A

Undulating, wave-like, sinusoidal

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19
Q

Flagella

Prokaryotic

A

Rotatory

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20
Q

Only vertebrate cell that has flagella

A

Sperm

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21
Q

Both cilia and flagella have the same ________ arrangement

A

9+2 pattern

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22
Q

Bending of cilia and flagella is driven by the arms of a motor protein _____

A

Dynein

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23
Q

Drugs that inhibit microtubules

Anti - gout

A

Colchinine

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24
Q

Disrupts microtubules that facilitate the movement of WBC towards the site of inflammation to lessen inflammation

A

Colchicine

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25
Q

Drug that inhibit microtubules

Anti-fungal

A

Griseofulvin

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26
Q

Inhibit cellular division of fungus

A

Griseofulvin

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27
Q

Drug that inhibit microtubules
Chemotherapeutic agents
Stopping the mitosis of cancer cells

A

Vinbalstine

Paclitaxel

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28
Q

Rare generic disorder characterized by immobile cilia of the respiratory tract and the Fallopian tubes or sperm flagella

A

Kartagener Syndrome

Primary ciliary dyskinesia

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29
Q

Immobile cilia
Infertile
Dynein-deficient

A

Kartagener Syndrome

Primary ciliary dyskinesia

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31
Q

Forms microfilaments

A

Actin

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32
Q

Causes the bending of the cilia and flagella

A

Dynein

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33
Q

Monomeric globular

A

G-actin

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34
Q

At physiologic ionic strength and in the presence of magnesium, G-actin ____ noncovalently to form an insoluble double helical filament

A

Polymerizes

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35
Q

Has a pitch or repeating structure every 35.5 nm

A

F-actin

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36
Q

Function of microfilament

A

Resist tension

Form a 3D network

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37
Q

The shape of the microvilli in the intestinal cell are ____, anchored to a network of intermediate filaments

A

Supported by microfilaments

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38
Q

Thicker filaments composed of a motor protein, _____, interdigitate with the thinner actin fibers

A

Myosin

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39
Q

In other cells, less organized ____ cause localized contraction

A

Actin-myosin aggregates

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40
Q

Contracting belt of microfilaments divide the cytopalsm of animal cells during the cell division, also termed as ____

A

Cytokinesis

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41
Q

Localized contraction also drives ______, in which pseudopodia extend and contract through the reversible assembly and contraction of actin subunits into microfilaments

A

Amoeboid movement

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42
Q

Clathrin-mediated endocytosis, also referred to as _____, occurs at a membrane indentions where the triskeion-shaped protein clathrin accumulates

A

Receptor-mediated endocytosis

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43
Q

Filaments with an axial periodicity of 21 nm and a diameter of 8-10 nm that is intermediate between the other two

A

Intermediate filaments

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44
Q

More stable and permanent fixtures of the cytoskeleton than the other two classes

A

Intermediate filaments

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45
Q

Functions of intermediate filaments

A

Bearing tension
Reinforce cell shape and fix organelle location
Relatively stable components of the cytoskeleton
Rather deformable proteins that can be stretched severla times their initial length

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46
Q

Most types of IF are cytoplasmic, ____ are nuclear

A

Lamins

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47
Q

Cell-cell adhesion

A

Desmosomes

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48
Q

Cell-matrix adhesion

A

Hemidesmosomes

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49
Q

At the cell membrane, some keratins interact with ____ and ____ via adapter proteins

A

Desmosomes; hemidesmosomes

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50
Q

Distribution of IF

Lamins

A

Nuclear lamina

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51
Q

Distribution of IF

Keratins

A

Epithelial lining, hair, nail (Type I-acidic)

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52
Q

Distribution of IF

Desmin

A

Muscle

53
Q

Distribution of IF

Vimentin

A

Various mesenchymal cells

54
Q

Distribution of IF

Glial fibrillary acid protein

A

Glial cells

55
Q

Distribution of IF

Peripherin

A

Neurons

56
Q

Distribution of IF

Neurofilaments (Low, High, Medium)

A

Neurons

57
Q

Two diseases due to abnormalities in IF

A

Hutchinson-Gilford Progeria

Epidermolysis Bullosa Simplex

58
Q

Important for structural scaffolding of the nucleus

A

Lamin A

59
Q

Mutations in the gene encoding ____ and ____ causes Hutchinson-Gilford Progeria

A

Lamin A and Lamin C

60
Q

Hutchinson-Gilford Progeria

Appearance of ____

A

Accelerated aging

61
Q

Mutations in genes encoding _____ causes epidermolysis bullosa simplex

A

Various keratins

62
Q

In epidermolysis bullosa simple, there is a diminished capacity of various layers of the skin to resist mechanical stresses due to abnormalities in keratin structure as manifested by _____

A

Blistering

63
Q

Hollow tubes, wall with 13 tubulin molecules

A

MIcrotubules

64
Q

Fibrous proteins supercoiled into the thicker cables

A

Intermediate Filaments

65
Q

2 intertwined strands of actin

A

Microfilaments

66
Q
Maintain cell shape (tension bearing elements)
Changes in cell shape
Muscle contraction
Cytoplasmic streaming
Cell motility and division
A

Microfilament

67
Q

Maintain cell shape (compresion-resisting girders)
Cell motility
Chromosome movement in cell division
Organelle movement

A

Microtubules

68
Q

Maintain cell shape
Anchorage of nucleus and other organelles
Formation of nuclear lamina

A

Intermediate filaments

69
Q

Most mammalian cells are located in tissues surrounded by a complex _____, which is a major component of connective tissue

A

ECM

70
Q

ECM is a _____ component present within all tissues and organs

A

Noncellular

71
Q

ECM initiates crucial biochemical and biomechanical required for tissue ____, ____ and ____

A

Morphogenesis, differentiation, homeostasis

72
Q

Functions of ECM

A
Structural support
Compartmentalize tissues
Provide rigidity
Signaling
Highway for cell migration during development, in normal tissue maintenance, and in injury or disease
73
Q

Composition of ECM

A

Water, protein, polysaccharide

74
Q

3 major classes of biomolecules (ECM)

A

Structural proteins
Specialized proteins
Proteoglycans

75
Q

Most abundant protein in animals

A

Collagen

76
Q

Collagen has _____ structure containing three alpha-polypeptide chains arranged in right-handed supercoil

A

Triple helix

77
Q

3 AA for collagen

A

Glycine, proline, hydroxyproline

78
Q

Types of Collagen

A
Fibril-forming
Network-forming
Fibril-associated collagen with interrupted triple helices
Anchoring
Beaded-filament forming
79
Q

Continuous, regular arrangement results in characteristic D period of 67nm

A

Fibril-forming collagen

80
Q

Examples of fibril forming collagen

A

I, II, III, V, VI

81
Q

Forms network in basement

A

Collagen IV

Network-forming collagen

82
Q

Molecular sieving

Molecular filtration

A

Network-forming

83
Q

Examples of network-forming collagen

A

Type IV, VII, X

84
Q

Short collagens with interruptions

Linked to collagen II and carries a GAG chain

A

Fibril-associated collagens with interrupted triple helices

85
Q

Found at the surface of fibril-forming collagen

A

Fibril-associated collagens with interrupted triple helices

86
Q

Examples of FACITs

A

IX, XII, XIV

87
Q

Provide functioning integrity by connecting epithelium to stroma

A

Anchoring collagen

88
Q

Example of anchoring collagen

A

Type VII

89
Q

Form structural links with cells

Type VI

A

Beaded-filament forming

90
Q

Collagen type

Reticulin

A

Type III

91
Q

Collagen type

Cartilage

A

Type II

92
Q

Collagen type

Basement membrane

A

Type IV

93
Q

Collagen type

Bone

A

Type I

94
Q

Collagen synthesis

Undergoes _____ before becoming part of the extracellular collagen fiber

A

Posttranslational modification

95
Q

Precursor of collagen

A

Preprocollagen

96
Q

Cardinal principle in the biosynthesis of collagen

A

Self-assembly

97
Q

Important cofactor in the hydroxylation of selected proline and lysine

A

Vitamin C

98
Q

Once formed, collagen is metabolically stable. Breakdown of which is increased during _____ and ____.

A

Starvation

Inflammatory States

99
Q

Excessive collagen deposition in the liver fibrosis due to prolonged injury to the tissue

A

Hepatic cirrhosis

100
Q

Collagen defects

Collagen I

A

Osterogenesis imperfecta

101
Q

Collagen defects

Collagen I and V

A

Ehlers Danlos syndrome

102
Q

Collagen defects

Collagen IV

A

Alport Syndrome

103
Q

Collagen defects

Collagen III

A

Certain arterial aneurysms

104
Q

Collagen defects

Collagen VI

A

Ullrich muscular dystrophy

105
Q

Reticulin fibers cannot hold integrity of your vascular structures

A

Certain arterial aneurysms

106
Q

Collagen defects

Collagen IX and XI

A

Certain chondrodysplasias

107
Q

Bone fragility, short stature, bone deformities, teeth abnormality, gray-blue sclera, hearing loss

A

Osteogenesis Imperfecta

108
Q

Osteogenesis imperfecta is caused by mutatation in either type I collagen ______

A

COL1A1 or COL1A2

109
Q

Liver spots on skin, spongy gums, bleeding from mucous membane, depresion, immobility

A

Scurvy

110
Q

____ is required for prolyl hydroxylase and lysyl hydroxylase activities

A

Ascorbate

111
Q

Elastin is important in ____ and _____ in tissues

A

Extensibility and elastic recoil in tissues

112
Q

Exhibits a variety of random coil conformations that permit _____ and ____

A

Stretch and subsequent coil

113
Q

Large glycoproteins whose primary structures are dominated by cbEGF domains that in the presence of calcium, adopt a rodlike structure

A

Fibrillin

114
Q

Structural component of microfibril

Secreted ECM by fibroblasts and becomes incorporated into the insoluble microfibrils

A

Fibrillin-1

115
Q

Provide a scaffold or deposition of elastin

A

Microfibril

116
Q

Caused by dominant fibrillin-1 mutations
Skeletal, ocular, cardiovascular defects
Deficiency of elastin-associated microfibrils

A

Marfan syndrome

117
Q

Syndrome that may result from alterations in cell signalling

A

Marfan syndrome

118
Q

Hyperaerated lung

Damage to the lung air sacs that affects breathing

A

Emphysema

119
Q

Increased alveolar size reduces the surface area for gas exchange

A

Emphysema

120
Q

Elastic fiber biogenesis
Assembly of microfibrils&raquo_space; association of tropoelastin aggregates with the microfibrils&raquo_space; crosslinking of tropoelastins with each other by _____ to form polymers

A

Lysyl oxidase

121
Q

Primary protein component of the basal lamina

A

Laminin, entactin, type IV collagen

122
Q

Basement membranes are involved in a multitude of biological processes: __, ___, ___

A

Cell proliferation
Cell differentiation
Cell migration

123
Q

Maintain cell polarization and organization as well as tissue structure

A

Basement membrane

124
Q

Basement membrane acts as _____ in the kidney between vasculature and the urinary space

A

Filtration barrier

125
Q

Laminins

3 elongated polypeptide chains (A, B, B2) linked together to form _____

A

Elongated cruciform shape

126
Q

Binding site for type IV collagen, heparin, integrins on cell surface

A

Laminin

127
Q

Assemble into trimers in the ER and are secreted as trimers intro extracellular space

A

Laminin Trimer Polymerase

128
Q

Full-sized laminin trimers can ____ into a macromolecular network through a short-arm interactions

A

Self-polymerize